There is an affinity between conventional refrigerants and lubricants such that, in refrigerant compressors, each is normally present in the other. For lubricants specifically, there can be problems associated with refrigerant gas being delivered to the lubrication system. This can be caused by outgassing taking place in the lubricant drawn into the lubrication system as a result of a reduction in pressure. Also, foam produced as a result of agitation of the lubricant by the lubricant pump structure may be drawn into the lubrication system. Specifically, in a semi-hermetic reciprocating compressor having an oil feed to the oil pump passing to the center of the rotating crankshaft, the oil enters through a hole in the drive tang which drives the oil pump rotor. Since the drive tang is bolted on and rotates with the crankshaft, the bolt heads and drive tang agitate the oil/refrigerant mixture producing foam that enters the oil pump. The more foam or gas that enters the oil pump, the less volume left for pumping oil.